Pk thpp

Tertiapin-Q (STT-170, Alomone Labs), CGP54626 (1088, Tocris), baclofen (0417, Tocris), linopirdine (1999, Tocris), XE991 (2000, Tocris), PK-THPP (5338, Tocris), spadin (5594, Tocris), and tolbutamide (T0891, dissolution with alcohol, Sigma) were used in whole-cell patch clamp mode. Kynurenic acid (K3375, Sigma), picrotoxin (1128, Tocris), and tetrodotoxin (T-550, Alomone Labs) were used to block synaptic currents. All solutions used in this study were made according to manufacturer’s specifications, and stock solutions of all drugs were dissolved in autoclaved de-ionized water unless specifically stated.

All drugs were obtained from Sigma-Aldrich (MO, USA), except for E-4031, PK-THPP, ML-365 (Tocris, MN, USA), Sub-P (Enzo Life Sciences, NY, USA), and TTX (Abcam Biomedicals, Cambridge, UK).
DIDS was freshly prepared as a 0.5 M and chromanol 293B as a 0.1 M stock solution in DMSO. Nifedipine was prepared as a 5 mM stock solution in ethanol. E-4031 and TTX were prepared as a 5 and 30 mM stock solution in distilled water. Senktide was prepared as a 1 mM stock solution in ethanol. PK-THPP and ML-365 were prepared as a 1 mM stock solutions in DMSO. Spadin was prepared as a 1 mM Stock solution in distilled water. ZnCl₂ was prepared as a 100 mM stock solution in distilled water. All stock solutions were diluted appropriately before use. Sub-P was freshly dissolved at its final concentration. DIDS and nifedipine were stored in the dark.

All drugs were administered via bath ACSF perfusate. A selective NK-1 receptor antagonist, sendide, was obtained from Enzo (Farmingdale, NY). A selective NK3 receptor antagonist SB223412 (SB); a selective TASK-1 channel blocker ML365, a selective TASK-3 channel blocker, PK-THPP, and 1,2,3,4-tetrahydro-6-nitro-2,3-dioxobenzoquinoxaline-7-sulfonamide (NBQX), 3-([(3,4-dichlorophenyl)methyl]amino]propyl)diethoxymethyl)phosphinic acid (CGP), D-2-amino-5-phosphonovalerate (AP5), SR95531 (gabazine), tetrodotoxin (TTX), and bicuculline were obtained from Tocris Bioscience (Ellisville, MO, United States). SP and picrotoxin were purchased from Sigma–RBI (Natick, MA, United States). Different concentrations of SP were perfused for 6 to 20 min at a flow rate of 1.8–2 ml/min. The synaptic responses over the final 5-min period of each concentration exposure were analyzed.